Two compartment motor

ABSTRACT

A two compartment motor has a frame, a pair of end shields disposed adjacent opposing ends of the frame to define a first compartment, a stator winding supported by the frame within the first compartment, an armature rotatably supported by the end shields and disposed within the first compartment adjacent the stator winding, a cover mounted to the motor adjacent one of the end shields to define a second compartment between the cover and the end shield, and a control plate mounted within the second compartment. The control plate serves as a mounting surface for securing a plurality of electrical components used in the control and operation of the motor in position within the second compartment. The control plate is a molded plastic component having integrally formed mounting mechanisms for at least one of the electrical components. The electrical components may include a starting capacitor, voltage and/or speed control switches, an overload device and electrical terminals. Ventilation openings, lead openings and shields may also be integrally formed in the control plate. The plate may be provided with recesses to accommodate electrical connectors, a centrifugal switch and other components. A method of assembling the motor includes mounting the plurality of components to the control plate to form a sub-assembly prior to connecting this sub-assembly to the other components of the motor.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates generally to electric motors and, moreparticularly, to a two compartment electric motor and a method ofmanufacturing a two compartment electric motor.

Single phase induction motors are manufactured in a variety of types andconfigurations. In addition to the stator, armature and other primarymotor compartments, some types and configurations include electrical orelectronic components which are used to modify operating characteristicsfor particular applications. Examples of such motors are resistancestart, reactor start, capacitor start, permanent split capacitor, andcapacitor start-capacitor run motors. These different types of motorsare characterized by different speed-torque characteristics, and may bedesigned to provide different theoretical maximum efficiencies. For someapplications, particularly those where high starting torque is required,part of the windings in a motor may be designed and arranged to serve asauxiliary or starting windings which are energized during initialexcitation of the motor, but which are deenergized as the motor comes upto a predetermined speed. Deenergization of such windings is oftenaccomplished by a centrifugal switch, or other appropriate device.

In some applications, and especially those applications of motors usedto drive pumps such as jet pumps or swimming pool pumps, capacitors,circuit controlling switches (e.g., speed control switches, voltagecontrol switches, overload devices, etc.), and other electricalcomponents are mounted to one of the motor end frames to facilitateaccess thereto. To provide protection from moisture, dust and othercontaminants, such components are often mounted in a closed "controlcompartment" which is disposed immediately adjacent the "motorcompartment" which houses the armature and other primary motorcomponents.

U.S. Pat. No. 4,593,163, which is commonly assigned to the assignee ofthe present invention, discloses a two compartment motor in whichcomponents such as a starting capacitor, a thermal protector, a terminalboard and motor circuit controlling switch assembly (e.g., a startingswitch assembly), and a manually actuable switch are mounted to an endshield of an induction motor assembly. A thermoplastic molded cover isfastened to the motor with axially directed mounting screws. The endshield to which the components are mounted and the molded plastic coverdefine a "control compartment" in which the subject electricalcomponents are housed.

An object of the present invention is to provide an improved twocompartment motor design.

Another object of the present invention is to provide a two compartmentmotor design which may be more easily and reliably manufactured.

Yet another object of the present invention is to provide a twocompartment electric motor design which includes a control plate in thecontrol compartment to which a plurality of electrical components may beconveniently mounted.

Yet another object of the present invention is to provide a twocompartment motor design in which a plurality of electrical controlcomponents may be premounted to a control plate to form a sub-assemblyprior to the assembly of the control compartment of the motor.

Still another object of the invention is to provide a two compartmentmotor with improved ventilation features which may be integrally formedin the control plate.

These and other objects of the invention are achieved in a twocompartment motor which comprises a frame, a pair of end shieldsdisposed adjacent opposite ends of the frame to define a firstcompartment, stator windings supported by the frame within the firstcompartment, an armature rotatably supported by the end shields anddisposed within the first compartment adjacent the stator windings, acover mounted to the motor adjacent one of the end shields to define asecond compartment between the cover and the end shield, and a controlassembly mounted within the second compartment. The control assemblycomprises a control plate, a plurality of electrical components, andmounting means for securing the electrical components in position on thecontrol plate. In one embodiment of the invention, the control plate isa molded plastic component and the mounting means is integrally formedor molded with the control plate. The electrical components may includea starting capacitor. In this case, the control plate may be formed withopposed, integrally molded, resilient fingers for securing the startingcapacitor to the control plate. The components may also include avoltage selection switch, and at least a portion of the switch may beintegrally molded with the control plate. Similar switches may beprovided for speed selection or other purposes.

The components mounted to the control plate may also include an overloaddevice, and one or more electrical terminals used, for example, as atermination point for electrical conductors supplying power to themotor. In the case of the overload device, the control plate includesintegrally formed means, such as one or more openings to receivethreaded fasteners, for securing the overload device to the controlplate. The control plate may also be provided with a plurality ofintegrally formed ventilation openings for providing a flow ofventilating air to or from the motor.

In one embodiment of the invention, the armature includes a shaft whichextends into the second compartment and through the control plate. Anintegrally formed shield to guard against unintended contacts betweenthis portion of the shaft and the electrical components and conductorswithin the second compartment may be provided on the control plate. Thisembodiment of the motor further comprises a centrifugal switch assemblyhaving a rotatable portion mounted on the shaft. An integrally moldedrecess for receiving and shielding the rotatable portion of thecentrifugal switch assembly is provided on one side of the controlplate. An actuator portion of the switch may be mounted by means ofintegrally formed mounting means to an opposing side of the controlplate. An opening in the control plate is provided to allow interactionbetween the actuator portion of the switch assembly and the rotatableportion to control an electrical circuit.

The control plate may also be provided with a recess for receivingmating electrical conductors which electrically connect the statorwindings to one or more of the electrical components in the secondcompartment. In this embodiment, a first electrical connector isprovided and connected by conductors to at least one of the electricalcomponents in the second compartment. This conductor may extend throughan opening in the control plate such that the connector is disposedbetween the control plate and the adjacent end shield. A secondconnector is provided and is connected by conductors to the statorwindings. These conductors extend through an opening in the end shieldsuch that the second connector is also disposed between the controlplate and the end shield. The control plate is formed with an integrallymolded recess adapted to receiving the mated first and secondconnectors.

Another aspect of the present invention relates to the end shield whichlies adjacent the cover to define the second compartment and which has a"skeleton" construction. This end shield comprises a central portion, acircumferential rim portion, and a plurality of radially extendingspokes connecting the central portion to the circumferential rimportion. The end shield is provided with at least one relatively largeopening between the central and circumferential rim portions and betweenadjacent ones of the radially extending spokes to allow for the passageof ventilating air and electrical conductors from the first to thesecond compartments. The central portion of the end shield comprises afirst recess on a first side thereof for receiving an armaturesupporting bearing therein. A second recess may be provided on a second,opposing side thereof for providing clearance for the rotating portionof the centrifugal switch assembly. The end shield may also be providedwith an integrally formed conduit receiving opening. The end shield ispreferably formed of a one-piece construction from a material such ascast aluminum. The conduit receiving opening is formed in an upstandingportion of the casting. A step-like shoulder is provided around at leasta portion of the conduit opening and is adapted to interact with an edgeof the cover to provide a seal to prevent entry of dust, moisture andother contaminants. At least one locating boss may be formed on eitherthe circumferential rim portion or on one of the spokes of the endshield to provide a mechanism for aligning the end shield and thecontrol plate in a preferred relative orientation.

In one embodiment of the invention, the cover comprises a one-piece,molded plastic element. An integrally molded shield may be provided onan interior surface of the cover for shielding an end portion of therotating shaft of the armature from the electrical components andconductors in the second compartment. The shield comprises a generallyarcuately shaped element extending around at least a portion of therotating shaft. The cover is a cup-shaped element having a peripheraledge formed to abut portions of the control plate and the adjacent endshield so as to effectively define the second compartment and shield theelectrical components from view and contamination.

In one embodiment of the invention, the voltage or speed selectionswitch, which may be among the plurality of components on the controlplate, comprises a movable portion and a stationary portion. Thestationary portion is integrally formed in the control plate. Thisportion comprises at least one electrical terminal mounted in thecontrol plate and adapted for mating with an electrical conductor in themovable portion. In a preferred embodiment of the switch, at least twoelectrical terminals are mounted in the control plate, and conductormeans for electrically connecting the terminals is provided in themovable portion. The switch means has a plurality of engaged positionswherein the movable portion is electrically engaged with the stationaryportion, and a disengaged position wherein the movable portion isselectively movable to or between first and second engaged positions.The stationary portion comprises one or more arcuate portions whichextend outwardly from the control plate. The movable portion is disposedadjacent the control plate within an area defined by the arcuateportions. At least one of the arcuate portions has an inwardly andtransversely extending lip for engaging an edge portion of the movableswitch portion to prevent the movable switch portion from being easilyremoved from the immediate vicinity of the control plate.

A preferred method of making a two compartment motor constructed inaccordance with the present invention comprises the steps of: mountingthe plurality of control components to the control plate; mounting thestator windings within the frame; rotatably supporting the armaturebetween the end shields and attaching the end shields to the frame suchthat the frame and the end shields define a first compartment and thestator windings and armature are disposed within the first compartment;mounting the control plate adjacent one of the end shields andelectrically connecting one or more of the plurality of components tothe stator windings; and mounting the cover adjacent the control plateand end shield to define the second compartment which encloses thecontrol plate and components. The method may include the additional stepof forming the control plate with integral means for mounting at leastone of the plurality of control components to the control plate.Additional steps may include interconnecting the plurality of controlcomponents with a plurality of electrical conductors, terminating one ormore of the conductors in a first electrical connector, connecting thestator windings to a second electrical connector, and matinglyconnecting the first and second electrical connectors. The control platemay be specially formed for receiving the mated first and secondconnectors to secure the connectors in position between the end plateand the control plate. The forming step may also include forming atleast a portion of a voltage or speed control switch integrally with thecontrol plate. An additional step may involve mounting a rotatableportion of a centrifugal switch on a shaft of the armature between thecontrol plate and the adjacent end shield. In this case, the formingstep may additionally comprise forming the control plate to includemeans for mounting a stationary portion of the centrifugal switch to thecontrol plate.

Other objects, advantages and novel features of the present inventionwill become apparent from the following detailed description of theinvention when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a two compartment motor constructed inaccordance with the principals of the present invention.

FIG. 2 is a bottom view of the two compartment motor of FIG. 1.

FIG. 3 is a partially exploded view of the motor of FIGS. 1 and 2.

FIG. 4 is a plan view of an end plate for a motor constructed inaccordance with the present invention.

FIG. 5 is a cross-sectional view of the end plate of FIG. 4.

FIG. 6 is a plan view of one side of a control plate, withoutcomponents, constructed in accordance with the principals of the presentinvention.

FIG. 7 is a plan view of the control plate of FIG. 6 with electricalcomponents mounted thereon.

FIG. 8 is a plan view of the other side of the control plate of FIG. 6.

FIG. 9 is a plan view of the other side of the control plate of FIG. 7.

FIG. 10 is a partial plan view of the control plate of FIG. 7 showingthe voltage control switch set in the low position.

FIG. 11 is a cross-sectional view taken along line 11--11 of FIG. 10.

FIG. 12 is a cross-sectional view taken along line 12--12 of FIG. 6.

FIG. 13 is a plan view of the inside of a cover for one compartment ofthe two compartment motor of the present invention.

FIG. 14 is a cross-sectional view taken along line 14--14 of FIG. 13.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of a two compartment motor 10constructed in accordance with the present invention. Motor 10 has afirst compartment which is defined by a first end shield 12, a secondend shield 14 and a generally cylindrical frame 16. Frame 16 providessupport for stator windings (shown in FIG. 3), while end shields 12 and14 are fitted with bearings to rotatably support an armature assemblywithin the first compartment adjacent the stator winding, as iswell-known in the art. Armature shaft 18 extends from one end of motor10 and is threaded, keyed or otherwise adapted for coupling to a load.End shield 12 is provided with a plurality of mounting lugs 20 which areused to securely mount motor 10 in operating position adjacent the load.

Motor 10 includes a second compartment (which may be referred to as thecontrol compartment) which is generally defined by end shield 14 and amolded plastic cover 22. As discussed in more detail below, the controlcompartment is used to house a plurality of electrical components usedin the control and operation of motor 10. Cover 22 is secured to motor10, as illustrated in more detail in FIG. 3, by threaded, hex-head screw24. Electrical access to the control compartment is provided by aconduit receiving opening 26 which is integrally formed in end shield14.

FIG. 2 is a bottom view of motor 10 in which a plurality of ventopenings 28, 30 and 32 are visible. Openings 28, 30 and 32 areintegrally formed in a control plate which will be described in detailin connection with FIGS. 6-9 below. Openings 28 and 30 are relativelyshort, narrow openings which extend from the lateral portions of thebottom of motor 10 to the lower regions of opposing sides of motor 10,as shown in FIG. 1. Openings 32 are relatively long and wide openingswhich are laterally centered along the bottom of motor 10. Thisarrangement is intended to provide adequate ventilation and airdischarge channels for the motor, while reducing contamination of thetwo motor compartments with dust and moisture.

FIG. 3 shows an exploded view of motor 10 in which the major componentsare visible. The upper left-hand portion of FIG. 3 shows the majorcomponents which define the first compartment of two compartment motor10. These components include end shield 12, frame 16 and end shield 14.As noted above, stator windings 34 are supported by frame 16 within thefirst compartment. An armature 36 is rotatably supported by end shields12 and 14 adjacent stator windings 34. Armature shaft 18 extends fromthe first compartment through end plate 12 for connection to a load aspreviously discussed. On the other end of motor 10, shaft 18 extendsthrough end shield 14 into the second compartment defined by cover 22and end shield 14. This end of shaft 18 is provided with a slot 38 andwrench flats 40 to facilitate manual rotation of, or to secure againstrotation of, armature 36 after the opposing end of shaft 18 is connectedto a load. Shaft 18 is also provided with two circumferential grooves 42which accept two locking clips 44. Clips 44 secure centrifugal speedswitch assembly 46 in position on shaft 18. A plurality of electricalconductors 43, which are electrically connected to stator windings 34,extend from the first compartment through end plate 14 and terminate inan electrical connector 45.

Mounted within the second compartment of motor 10 is a control plate 48which, in the embodiment illustrated, is a one-piece molded plasticstructure which provides a mounting base for securing a plurality ofelectrical components used in the control and operation of motor 10 inposition within the second compartment. The exact structure of theillustrated embodiment of control plate 48 will be discussed in detailin connection with FIGS. 6-9 below. Control plate 48 is mounted to motor10 by a pair of long bolts 50 which extend through control plate 48, endshield 14 and frame 16 to engage threads formed in end shield 12. Aneyelet 51 is provided between control plate 48 and end shield 14 (seeFIGS. 8 and 9). Alternatively, control plate 48 can also be secured bynuts threaded onto the ends of bolts which extend through end shield 12,frame 16, end shield 14 and control plate 48. Bolts 50, along with anadditional pair of bolts 52, also serve to secure end shields 12 and 14to frame 16. In the assembly process, this arrangement allows controlplate 48 to be separately mounted to the sub-assembly which includes thefirst compartment of motor 10. Separate, shorter mounting bolts may alsobe used to secure control plate 48 to, for instance, threaded holes inend shield 14.

In the illustrated embodiment, cover 22 mounts, via screw 24 whichextends through opening 25, to a threaded screw-receiving boss 54 whichis an integrally formed element of control plate 48. Although screw 24is shown separated from cover 22 in the partially exploded view of FIG.3, screw 24 is preferably "captured" in opening 25 so as to remain withcover 22 upon removal from motor 10. In this embodiment of theinvention, both cover plate 48 and cover 22 are molded plasticcomponents.

Also shown in FIG. 3 is a ground screw 53 which threads into an openingin boss 78 of end shield 14 to provide a convenient means by which toconnect the metal components of motor 10 to a ground wire (shown indashed lines) provided by the user.

FIG. 4 is a plan view of end shield 14 of motor 10. End shield 14utilizes a "skeleton" design which includes a central portion 60, fourradially-extending spokes 62 and a circumferential portion 64. Thisarrangement provides relatively large openings 66-69 for the passage ofventilating air and power conductors through end shield 14. Withreference to FIGS. 4 and 5, central portion 60 of end shield 14 includesa generally circular, annular recess 70 which faces away from armature36 when end plate 14 is assembled in motor 10. Recess 70 providesclearance for centrifugal switch assembly 46. Central portion 60 furtherincludes, on the side of end shield 14 which faces the armature, amachined recess 72 which is adapted to receive the bearing (not shown)which supports the respective end of armature 36.

End shield 14 is provided with four holes for receiving mounting bolts50 and 52. Holes 74, which receive bolts 52, are provided withintegrally formed bosses 76 which provide a bearing surface for theheads of bolts 52, and which allow for use of a common bolt length.Mounting holes 77 are formed flush (i.e., without bosses) to provide aflat mating surface for control plate 48. Clearance openings 188 and 202(FIG. 6) are provided in control plate 48 for bosses 76 and the heads ofbolts 52. An additional raised projection or boss 78 is provided as anadditional locating and orientation landmark for control plate 48, andprovides a grounding point for connecting the metallic elements of motor10 to a user supplied ground wire (see FIG. 3). Openings 80 and 82 areprovided in an opposing pair of spokes 62 to allow control plate 48 tobe mounted directly to end shield 14, independently of bolts 50, ifdesired. This arrangement allows for the possibility that the motor maybe shipped as a "parts" motor without end shield 12.

An additional feature of end shield 14 is integrally formed conduitreceiving opening 26. Opening 26 is integrally formed in an upstandingportion 83 of end shield 14. Opening 26 is threaded to receive a conduitnipple to facilitate connection of the motor to an external powersource. A recessed shoulder 84 is formed around three sides of opening26 to mate with a similarly shaped cut-out 86 (FIGS. 3 and 14) in cover22 to provide a step flange-type seal around the three sides of opening26.

End shield 14 is also provided with a raised projection 87 on theoutwardly facing side surface of circumferential portion 64. Projection87 extends substantially parallel to the longitudinal axis of motor 10across substantially the full width of circumferential portion 64 of endshield 14. The function of projection 87 is to provide an alignment andanti-rotation feature for a separately mounted "bonding lug" such as iscommonly used in the swimming pool industry.

In the embodiment of the invention illustrated, end shields 12 and 14are formed in one piece of a metallic material, such as cast aluminum.

FIGS. 6 and 7 show plan views of the exterior side of control plate 48,without and with a plurality of electrical components mounted thereon,respectively. The various features of control plate 48 and thecomponents will be described with reference to FIGS. 6 and 7, startingat the top or twelve o'clock position, as viewed in the figures, andmoving clockwise around the plate. Near the top of plate 48 is an area90 for mounting a portion of a centrifugal switch 92. Centrifugal switch92 has an actuator portion (210 in FIG. 9) which extends through anopening 94 formed in plate 48. Mounting holes 96 and 98 are alsoprovided in plate 48 to receive screws 100 and 102 which securecentrifugal switch 92 in position. The top surface 104 of centrifugalswitch 92 is provided with a plurality of slots (e.g., 106), some ofwhich receive male terminals (e.g., 108 and 110). In the embodimentshown in FIG. 7, two of these male terminals are shown connected tofemale terminals 112 and 114 which, in turn, are connected to electricalconductors 116 and 118, respectively. Openings 99 and 101 are providedin control plate 48, as shown in FIG. 6, to allow conductors such asconductors 116 and 118 to pass through control plate 48, as will bedescribed in additional detail below. The base of centrifugal switch 92serves to close and seal lead openings 99 and 101 so that separate sealstructures in connection with these openings are not needed. Anoutwardly projecting post 103 and an inwardly (i.e., into area 90)projecting member 105 are provided to serve as locating and orientingaids for switch 92.

Immediately below centrifugal switch 92 is integrally molded boss 54which, as previously discussed in connection with FIG. 3, receives screw24 to secure cover 22 in position. A pair of reinforcing gussets 120 and122 are integrally molded to provide additional support for boss 54.

Immediately adjacent centrifugal switch 92 is an opening 124 for one ofthe two mounting bolts 50. Adjacent opening 124 is a larger opening 126which provides clearance for boss 78 of end plate 14.

Adjacent opening 126, at approximately the three o'clock position, is apassageway 128. Passageway 128 is integrally formed in control plate 48and is aligned, when motor 10 is assembled, with conduit receivingopening 26 of end shield 14. Passageway 128 provides access to theinterior of the control compartment for a plurality of conductors (e.g.,130 and 132) through opening 126. Leads 130 and 132 terminate in femaleterminals 134 and 136. Female terminals 134 and 136 mate with upwardlyextending (i.e., out of the page) blade portions of S-shaped terminals138 and 140, respectively. With reference to FIG. 6, three sets ofmounting openings are provided for the S-shaped terminals. Each setincludes a relatively small opening 142 which is sized to receive arivet, screw or other fastening device 143 to mechanically secure theterminals to control plate 48. Each set further includes a larger recess144 to provide clearance for terminal screws, such as screws 146 and148, which may be used to secure spade terminals or other conductors inelectrical contact with the S-shaped terminals. Finally, each set ofmounting openings includes a rectangular slot 150 which receives adownwardly extending (i.e., into the drawing) male terminal whichextends through control plate 48 for mating with a female terminal onthe other side of control plate 48 (see FIG. 9). S-shaped terminals 138and 140 include a "lance" portion (not shown) to partially secure themto control plate 48.

In the center of control plate 48 is an opening 152 which providesclearance for armature shaft 18. Immediately adjacent opening 152 is anarcuate shield 154 which extends outwardly from control plate 48 (i.e.,out of the drawing in FIGS. 6 and 7) Shield 154, in conjunction withshield 226 of cover 22 (see FIG. 13), serves to shield terminals 134 and136 and conductors 130 and 132 from rotating armature shaft 18.

Adjacent passageway 128 is a voltage selector switch 156 shown with(FIG. 7) and without (FIG. 6) movable switch portion 158. An enlarged,cross-sectional view of switch 156 is shown in FIG. 11. Switch 156includes an outwardly extending arcuate portion 160 having inwardly andtransversely extending lips 162 near the top thereof to prevent or limitcomplete removal of portion 158 from its position adjacent plate 48. Aseparate arcuate shaped portion 164 is formed between the opposing endsof arcuate portion 160 to provide two gaps 166 and 168. Within thecircular area defined by arcuate portion 160 and 164 are a plurality ofopenings 170-174. At least some of these openings (i.e., 170-173) arefitted with electrical terminals, an exemplary one of which is shown inthe enlarged cross-sectional view of FIG. 11, and is designated byreference numeral 176. The female ends of each of the terminals 176receive one end of U-shaped conductors 178 and 180 which are part ofmovable portion 158. When movable portion 158 is engaged in the highposition (FIG. 7), conductors 178 and 180 connect a first set ofterminals 176. When movable portion 158 is engaged in the low position(FIG. 10), different pairs of terminals 176 are connected. The oppositeends of terminals 176 extend through plate 48 and are connected, such asby crimping, to electrical conductors illustrated, for example, byconductor 182.

Switch 156 is operated (i.e., moved from the high to low position orvice-versa}, by grasping upstanding portion 184 of movable portion 158and pulling portion 158 outwardly to disengage conductors 178 and 180from terminals 176 until edge portion 186 of portion 158 contacts lips162. Movable portion 158 is then rotated to the desired position andmoved inwardly to engage the ends of U-shaped conductors 178 and 180into terminals 176. This arrangement provides an easy, convenient andinexpensive mechanism for selecting between high and low voltagesettings. If desired, additional switch mechanisms of this type may beprovided for, among other things, speed selection.

Adjacent switch assembly 156 is an opening 188 to provide clearance forboss 76 and the head of bolt 52. Also adjacent switch 156 is opening190. Opening 190 aligns with opening 82 in end shield 14, and providesmeans by which secondary retention of control plate 48 can be achievedfor applications in which end shield 12 is not required.

Near the bottom (i.e., the six o'clock position) of plate 48 are theplurality of relatively large vent openings 32. These vent openings, incombination with the open "skeletal" construction of end shield 14,ensure adequate ventilation of motor 10. These features further allowfor simplified compliance with U.L. standards regarding molten metalprotection. The integrally formed air channels in control plate 48improve the air intake and discharge capabilities of the motor,resulting in reduced motor operating temperature rises.

Adjacent vent openings 32 is a mounting hole 192 which receives one ofthe bolts 50 for mounting plate 48 to end shield 14. Adjacent mountinghole 192, at approximately the nine o'clock position, are a plurality ofintegrally formed resilient fingers 194 which extend upwardly fromcontrol plate 48 (i.e., out of the drawings in FIGS. 6 and 7) whichreceive and hold starting capacitor 196 in position. Additional L-shapedprojections 198 are also provided to locate capacitor 196 axially withinthe resilient grip of fingers 194. A plurality of molded projections 200serve as stand-offs to laterally position capacitor 196 within the gripof fingers 194.

Adjacent integrally molded capacitor retaining fingers 194 is opening202 which provides clearance for boss 76 and the head of mounting bolt52. Adjacent opening 202 is opening 204. Opening 204 aligns with opening80 in end shield 14 to provide an alternative means for securing controlplate 48 to end shield 14.

FIGS. 8 and 9 show, respectively, the interior or back side of controlplate 48. The features of the back side of plate 48 will be discussedbeginning at the top or twelve o'clock position and movingcounterclockwise around the circumference of plate 48. To the extentfeatures discussed in connection with FIGS. 6 and 7 are shown unchangedin FIGS. 8 and 9 (for example, mounting holes 96 and 98, openings 124and 126, etc.), such features are identified with like reference numbersin all figures, but are not separately discussed below.

A recess, generally indicated by reference numeral 205, is provided nearthe top of control plate 48 to accommodate a multi-terminal electricalconnector 206 which is configured to mate with electrical connector 45(FIG. 3) which, in turn, is connected to conductors 43 which extend intothe first or motor compartment of motor 10. Connector 206 is connectedto a plurality of electrical conductors which, in turn, are connected tovarious ones of the electrical components mounted on control plate 48,including one or more of the conductors extending through opening 99.Conductors may also extend through opening 101 which is located on theopposite side of open area 205. Electrical connectors 45 and 206 allowthe electrical components on control plate 48 to be conveniently andreliably connected to the other major components (e.g., stator windings34) of motor 10 in a single operation to improve the quality andmanufacturability of the motor.

Inwardly of recess 205 and opening 94 is an annular wall 208 whichextends 360° around an inner circumference of plate 48. The innersurface of wall 208 defines a protected space for centrifugal speedswitch assembly 46. Extending into this space through a portion ofopening 94 is actuator 210 which interacts with a rotating portion ofswitch 46 to open or close an electrical circuit, via centrifugal switch92, when armature 36 reaches a specified rotational speed.

Adjacent recess 205 is opening 124 for one of the two mounting bolts 50.Both opening 124 and diagonally-disposed opening 192 are countersunk, asillustrated in FIG. 8, to receive metal eyelets 51 as illustrated inFIG. 9. Eyelets 51 better distribute the stresses placed upon controlplate 48 by the heads of bolts 50.

At the nine o'clock position in FIGS. 8 and 9 is the back surface 129 ofpassageway 128. Surface 129 is generally smooth and concavely curved(i.e., out of the paper) along either side of an axis which extendshorizontally through the center of control plate 48.

Inwardly of and on either side of surface 129 are opening 142 and recess144 and slots 150 which were discussed in connection with FIGS. 6 and 7.Female terminals 212 and 214 are shown connected to the male ends (whichare hidden from view by the female terminals) of S-shaped terminals 138and 140. Fasteners (i.e., rivets) 143 are visible in FIG. 9.

Adjacent surface 129, and inwardly of vent openings 28, is the portionof switch 156 which is integrally formed With control plate 48. Switch156 was previously discussed in connection with FIGS. 6, 7, 10 and 11above. Adjacent switch 156 are openings 188 and 190, vent openings 32,opening 192 and vent openings 30, all of which have been previouslydiscussed and will not be separately discussed in connection with FIGS.8 and 9.

At approximately the three o'clock position, as viewed in FIGS. 8 and 9,is a space 216 which is provided for mounting a thermal overload device218 to control plate 48. An integrally formed post 219 and a boss 220with an opening 222 for receiving a fastener 224 are provided formounting thermal overload 218. As with the other integrally formedfeatures discussed above, post 219 and boss 220 are preferably molded ofa plastic material to provide a one-piece, completely integratedstructure.

FIG. 12 is a cross-sectional view of control plate 48 taken along line12--12 of FIG. 6. Visible in FIG. 12 is upstanding arcuate portion 160.Portion 164 is shown in dashed lines. As is apparent in FIG. 12, portion164 is substantially shorter than portion 160 to provide clearance for"pointer" 169 which extends somewhat from movable portion 158 beyond theinner perimeter of the arcuate portions to more clearly indicate theswitch position. Also visible is shield 154 and boss 54 with opening 55for receiving screw 24. Adjacent boss 54 is space 90 which receivescentrifugal switch 92. Opposing space 90 is recess 205 which, asdiscussed above, is provided to receive electrical connectors 45 and206. Finally, recess 208 which defines clearance space for centrifugalswitch 46 is clearly shown in FIG. 12, as is opening 94 which providesclearance for actuator 210.

FIG. 13 shows an interior view of cover 22. Integrally molded in theinterior of cover 22 is an additional shield 226 which cooperates withshield 154 to protect terminals, wiring and other electrical componentsfrom the exposed end of rotating armature shaft 18. The exteriorcontours of cover 22 in the areas generally designated by referencenumerals 228 and 230 are molded to fit around and form a relativelytight seal with vent openings 28, 30 and 32. Cut-out 86, as previouslydiscussed, conforms to recessed shoulder 84 of end shield 14. As is thecase with control plate 48, cover 22, in the embodiment illustrated, ismolded from a plastic material.

The arrangement of the present invention allows for efficient assemblyof a high-quality two compartment motor. In the arrangement of thepresent invention, the electrical components referred to above, such asthe thermal overload, the capacitor, the voltage selection switch, theactuator for the centrifugal switch, and the terminals and wiring arepreassembled "off-line" with strict quality controls in a uniform andrepeatable fashion. The parts of the motor which make up and areenclosed in the first compartment may be assembled in a standard manner,with "skeleton" end shield 14 mounted to allow conductors 43 to extendthrough the open portions of the end shield. The rotatable portion of acentrifugal switch may be mounted to the armature, if appropriate. Thepreassembled control board is then brought to the motor and electricalconnectors 45 and 206 are connected in a single operation. The controlboard assembly is secured to either end shield or the frame. Cover 22 isthen positioned and secured, such as by screw 24, to complete theassembly.

From the preceding description of the illustrated embodiments, it isevident that the objects of the invention are attained. Although theinvention has been described and illustrated in detail, it is to beclearly understood that the same is intended by way of illustration andexample only and is not to be taken by way of limitation. The spirit andscope of the invention are to be limited only by the terms of theappended claims.

What is claimed is:
 1. A two compartment motor, comprising:a frame; apair of end shields disposed adjacent opposing ends of the frame todefine a first compartment; a stator winding supported by said framewithin said first compartment; an armature rotatably supported by theend shields and disposed within the first compartment adjacent thestator winding; a cover mounted to the motor adjacent one of said endshields to define a second compartment between said cover and said endshield; and a control plate mounted within said second compartments,said control plate comprising mounting means for securing a plurality ofelectrical components used in the control and operation of the motor inposition within said second compartment; wherein said control plate is amolded plastic component, and said mounting means for securing at leastone of said plurality of components is integrally molded in said controlplate; and wherein said control plate further comprises at least one of:(a) an integrally molded portion of a switch, (b) an integrally formedpassageway which is aligned with a conduit receiving opening formed inthe end shield for providing access to the interior of the secondcompartment for a plurality of conductors, (c) a plurality of integrallyformed ventilation openings for providing a flow of ventilating air toor from the motor, and (d) an integrally formed shield to guard againstunintended contacts between the rotating armature and the electricalcomponents and conductors within the second compartment.
 2. A twocompartment motor according to claim 1, wherein one of said electricalcomponents comprises a starting capacitor, and wherein said controlplate includes opposed integrally molded, resilient fingers for securingsaid starting capacitor to the control plate.
 3. A two compartment motoraccording to claim 1, wherein said plurality of electrical componentsincludes a speed selection switch, and wherein at least a portion ofsaid switch is integrally molded with said control plate.
 4. A twocompartment motor according to claim 1, wherein said plurality ofelectrical components includes a voltage selection switch, and whereinat least a portion of said switch is integrally molded with said controlplate.
 5. A two compartment motor according to claim 1, wherein saidplurality of electrical components includes an overload device, andwherein said control plate includes integrally formed means for mountingsaid overload device.
 6. A two compartment motor according to claim 1,wherein said control plate is provided with a recess for receivingmating electrical connectors which electrically connect the statorwinding to one or more of the electrical components in the secondcompartment.
 7. A two compartment motor according to claim 1, furthercomprising first and second mating electrical connectors, said firstconnector being electrically connected to at least one electricalconductor which is also connected to at least one of the electricalcomponents in the second compartment, and which extends through anopening in the control plate such that said first electrical connectoris disposed between the control plate and the adjacent end shield, saidsecond connector being electrically connected to at least one conductorwhich is also connected to the stator winding and which extends from thestator winding through the end shield such that said second electricalconnector is disposed between the control plate and the end shield, andwherein said control plate is provided with a recess adapted to receivethe mated first and second connectors.
 8. A two compartment motoraccording to claim 1, wherein said end shield is formed of a one-piececonstruction from a castable metallic material.
 9. A two compartmentmotor according to claim 1, wherein said cover comprises a one-piece,cup-shaped element having a peripheral edge formed to abut portions ofsaid control plate and said adjacent end shield so as to effectivelydefine said second compartment and shield the electrical components fromview and contamination.
 10. A two compartment motor according to claim1, wherein said armature comprises a shaft which extends into the secondcompartment, and wherein said motor further comprises a centrifugalswitch assembly having a rotatable portion mounted on said shaft.
 11. Atwo compartment motor according to claim 10, wherein said control platehas an integrally molded recess portion for receiving and shielding therotatable portion of the centrifugal switch assembly.
 12. A twocompartment motor according to claim 11, wherein said switch assemblyfurther comprises an actuator portion, and wherein said control plateincludes integrally formed mounting means for securing said actuatorportion in position.
 13. A two compartment motor according to claim 12,wherein said control plate has an opening formed adjacent said actuatorportion, and opening into said recess, to allow said actuator portion ofthe switch assembly to interact with said rotatable portion of theassembly.
 14. A two compartment motor according to claim 1, wherein saidend shield adjacent said cover comprises a central portion, acircumferential rim portion, and a plurality of radially extendingspokes connecting said central portion to said circumferential rimportion.
 15. A two compartment motor according to claim 14, wherein saidend shield is provided with at least one relatively large openingbetween said central and circumferential rim portions and betweenadjacent ones of said radially extending spokes for the passage ofventilating air and electrical conductors from the first to the secondcompartments.
 16. A two compartment motor according to claim 14, whereinsaid central portion comprises a first recess on a first side thereoffor receiving an armature-supporting bearing therein, and a secondrecess on a second, opposing side thereof for providing clearance for arotating centrifugal switch assembly.
 17. A two compartment motoraccording to claim 14, wherein said end shield adjacent said covercomprises at least one boss formed on said circumferential rim portionor on one of said spokes, and wherein said control plate comprises anopening adapted to receive said boss so as to align the end shield andcontrol plate in a preferred relative orientation.
 18. A two compartmentmotor according to claim 1, wherein said end shield adjacent said coveris provided with an integrally formed conduit receiving opening.
 19. Atwo compartment motor according to claim 18, wherein said end shieldfurther comprises a step-like shoulder formed around at least a portionof the conduit receiving opening and adapted to interact with an edgeportion of the cover to provide a seal to prevent entry of contaminants.20. A two compartment motor according to claim 1, wherein said covercomprises a one-piece, molded plastic element.
 21. A two compartmentmotor according to claim 20, further comprising shield means integrallymolded with an interior surface of said cover for shielding an endportion of a rotating shaft of the armature from the electricalcomponents in the second compartment.
 22. A two compartment motoraccording to claim 21, wherein said shield means comprises a generallyarcuately-shaped element extending around at least a portion of saidrotating shaft.
 23. A two compartment motor, comprising:a frame; a pairof end shields disposed adjacent opposing ends of the frame to define afirst compartment; a stator winding supported by said frame within saidfirst compartment; an armature rotatably supported by the end shieldsand disposed within the first compartment adjacent the stator winding;means adjacent one of said end shields for defining a secondcompartment; and a control assembly mounted within said secondcompartment, said control assembly comprising a control plate, aplurality of electrical components, and mounting means for securing saidelectrical components in position on said control plate; wherein saidcontrol plate is a molded plastic components, and wherein said mountingmeans for securing at least one of said plurality of components isintegrally molded in said control plate; and further comprising switchmeans having a movable portion and a stationary portion, and whereinsaid stationary portion is integrally formed in said control plate. 24.A two compartment motor according to claim 23, wherein said stationaryportion comprises at least one electrical terminal mounted in thecontrol plate and adapted for mating with a conductor in said movableportion.
 25. A two compartment motor according to claim 23, wherein saidstationary portion comprises at least two electrical terminals mountedin the control plate, and wherein said movable portion comprisesconductor means for electrically connecting said electrical terminals.26. A two compartment motor according to claim 23, wherein said switchmeans has an engaged position wherein said movable portion iselectrically engaged with said stationary portion, and a disengagedposition wherein said movable portion is rotatable relative to saidstationary portion.
 27. A two compartment motor according to claim 23,wherein said switch means has first and second engaged positions whereinsaid movable portion is electrically engaged with said stationaryportion, and a disengaged position wherein said movable portion isselectively movable between said first and second engaged positions. 28.A two compartment motor according to claim 23, wherein said stationaryportion comprises an arcuate portion extending outwardly from saidcontrol plate, and wherein said movable portion is disposed adjacentsaid control plate within an area defined by said arcuate portion.
 29. Atwo compartment motor according to claim 28, wherein said arcuateportion has an inwardly and transversely extending lip for engaging anedge portion of said movable portion to prevent said movable portionfrom being removed from the immediate vicinity of said control plate.